Cloning

Dolly the sheep, the first mammal cloned from a somatic (body) cell,
came into the world innocent as a lamb. However, soon after the
announcement of her birth in February 1997 (Wilmut et al.,
1997) she caused panic and controversy. An important, and for many
people troubling question arose: if the cloning of sheep is possible,
will scientists soon start cloning humans as well; and if they did,
would this be wrong or unwise?

For most people, Dolly was really a wolf in sheep’s clothing.
She represented a first undesirable and dangerous step to applying
reproductive cloning in humans, something that many agreed should never
be done. Only a small minority thought it was permissible, or even
morally obligatory to conduct further research into human reproductive
cloning. Some had no strong objections to it, but did not see any
reason to promote it either.

Dolly is now stuffed and set up for display in the National Museum
of Scotland. Many countries or jurisdictions have legally banned human
cloning or are in the process of doing so. In some countries, including
France and Singapore, reproductive cloning of humans is a criminal
offence. In 2005, the United Nations adopted a ‘Declaration on
Human Cloning’, which calls for a universal ban on human cloning.
The debate on human reproductive cloning seems to have drawn to a
close. However, since reproductive cloning of mammals has
become routine in several countries, there is reason to believe that at
some point in the future, humans will be cloned too. Moreover, even if
reproductive cloning will not be possible in the near future,
cloning for research and therapeutic purposes is likely to be.

This entry describes the most important areas of disagreement
regarding the ethics of cloning. I will focus on human cloning (as
opposed to animal cloning), since human cloning has been the focus of
the cloning debate.

Strictly speaking, cloning is the creation of a genetic
copy of a sequence of DNA or of the entire genome of an organism. In
the latter sense, cloning occurs naturally in the birth of identical
twins and other multiples. But cloning can also be done artificially in
the laboratory via embryo twinning or splitting: an early embryo is
split in vitro so that both parts, when transferred to a
uterus, can develop into individual organisms genetically identical to
each other. In the cloning debate, however, the term
‘cloning’ typically refers to a technique called somatic
cell nuclear transfer (SCNT). SCNT involves transferring the nucleus of
a somatic cell into an oocyte from which the nucleus and thus most of
the DNA has been removed. (The mitochondrial DNA in the cytoplasm is
still present). The manipulated oocyte is then treated with an electric
current in order to stimulate cell division, resulting in the formation
of an embryo. The embryo is (virtually) genetically identical to, and
thus a clone of the somatic cell donor.

Dolly was the first mammal to be brought into the world
using SCNT. Wilmut and his team at the Roslin Institute in Scotland
replaced the nucleus from an oocyte taken from a Blackface ewe with the
nucleus of a cell from the mammary gland of a six-year old Finn Dorset
sheep (these sheep have a white face). They transferred the resulting
embryo into the uterus of a surrogate ewe and approximately five months
later Dolly was born. Dolly had a white face: she was genetically
identical to the Finn Dorset ewe from which the somatic cell had been
obtained.

Dolly, however, was not 100% genetically identical to the
donor animal. Genetic material comes from two sources: the nucleus and
the mitochondria of a cell. Mitochondria are organelles that serve as
power sources to the cell. They contain short segments of DNA. In
Dolly’s case, her nuclear DNA was the same as the donor
animal; other of her genetic materials came from the mitochondria in
the cytoplasm of the enucleated oocyte. For the clone and the donor
animal to be exact genetic copies, the oocyte too would have to come
from the donor animal (or from the same maternal line –
mitochondria are passed on by oocytes).

Dolly’s birth was a real breakthrough, for it proved
that something that had been considered biologically impossible could
indeed be done. Before Dolly, scientists thought that cell
differentiation was irreversible: they believed that, once a cell has
differentiated into a specialized body cell, such as a skin or liver
cell, the process cannot be reversed. What Dolly demonstrated was that
it is possible to take a differentiated cell, turn back its biological
clock, and make the cell behave as though it was a recently fertilized
egg.

Nuclear transfer can also be done using a donor cell from
an embryo instead of from an organism after birth. Cloning mammals
using embryonic cells has been successful since the mid-1980s (for a
history of cloning, see Wilmut et al. 2001). Another
technique to produce genetically identical offspring or clones is
embryo twinning or embryo splitting, in which an early embryo is split
in vitro so that both parts, when implanted in the uterus, can
develop into individual organisms genetically identical to each other.
This process occurs naturally with identical twins.

However, what many people find disturbing is the idea of creating a
genetic duplicate of an existing person, or a person who has
existed. That is why the potential application of SCNT in humans set
off a storm of controversy. Another way to produce a genetic duplicate
from an existing person is by cryopreserving one of two genetically
identical embryos created in vitro for several years or
decades before using it to generate a pregnancy. Lastly, reproductive
cloning of humans could, in theory, also be achieved by combining the
induced pluripotent stem cell technique with tetraploid
complementation. Several research teams have succeeded in cloning mice
this way (see, for example, Boland et al. 2009). The technique
involves injecting mouse iPS cells in tetraploid embryos, i.e. embryos
with twice the normal number of chromosomes that cannot result in live
offspring. The resulting mouse pups are derived solely from the iPS
cells, which means that the tetraploid embryos only acted as a
substitute trophectoderm, which forms the placenta and other
nourishing membranes but which does not contribute to the ‘embryo
proper’.

Dolly is a case of reproductive cloning, the aim of which
is to create offspring. Reproductive cloning is to be distinguished
from cloning for therapy and research, sometimes also referred to as
‘therapeutic cloning’. Both reproductive cloning and
cloning for research and therapy involve SCNT, but their aims, as well
as most of the ethical concerns they raise, differ. I will first
discuss cloning for research and therapy and will then proceed to
outline the ethical debate surrounding reproductive
cloning.

Cloning for research and therapy involves the creation of an embryo
via SCNT, but instead of transferring the cloned embryo to the uterus
in order to generate a pregnancy, it is used to obtain pluripotent stem
cells. It is thus not the intention to use the embryo for reproductive
purposes. Embryonic stem cells offer powerful tools for developing
therapies for currently incurable diseases and conditions, for
important biomedical research, and for drug discovery and toxicity
testing (Cervera & Stojkovic 2007). For example, one
therapeutic approach is to induce embryonic stem cells to differentiate
into cardiomyocytes (heart muscle cells) to repair or replace damaged
heart tissue, into insulin-producing cells to treat diabetes, or into
neurons and their supporting tissues to repair spinal cord
injuries.

A potential problem with embryonic stem cells is that they will
normally not be genetically identical to the patient.
Embryonic stem cells are typically derived from embryos donated for
research after in vitro fertilization (IVF) treatment. Because
these stem cells would have a genetic identity different from that of
the recipient – the patient – they may, when used in
therapy, be rejected by her immune system. Immunorejection can occur
when the recipient’s body does not recognize the transplanted
cells, tissues or organs as its own and as a defense mechanism attempts
to destroy the graft. Another type of immunorejection involves a
condition called graft-versus-host disease, in which immune cells
contaminating the graft recognize the new host – the patient
– as foreign and attack the host’s tissues and organs. Both types
of immunorejection can result in loss of the graft or death of the
patient. It is one of the most serious problems faced in transplant
surgery.

Cloning for research and therapy could potentially offer a solution to this
problem. An embryo produced via SNCT using the patient’s somatic
cell as a donor cell would be virtually genetically identical to the
patient. Stem cells obtained from that embryo would thus also be
genetically identical to the patient, as would be their derivatives,
and would be less likely to be rejected after transplantation. Though
therapies using embryonic stem cells from SCNT embryos are not yet on
the horizon for humans, scientists have provided proof of concept for
these therapies in the mouse.

Embryonic stem cells from cloned embryos would also have significant
advantages for biomedical research, and for drug discovery and toxicity
testing. Embryonic stem cells genetically identical to the patient
could provide valuable in vitro models to study disease,
especially where animal models are not available, where the research
cannot be done in patients themselves because it would be too invasive,
or where there are too few patients to work with (as in the case of
rare genetic diseases). Researchers could, for example, create large
numbers of embryonic stem cells genetically identical to the patient
and then experiment on these in order to understand the particular
features of the disease in that person. The embryonic stem cells and
their derivatives could also be used to test potential treatments. They
could, for example, be used to test candidate drug therapies to predict
their likely toxicity. This would avoid dangerous exposure of patients
to sometimes highly experimental drugs.

Cloning for research and therapy is, however, still in its infancy
stages. In 2011, a team of scientists from the New York Stem Cell
Foundation Laboratory was the first to have succeeded in creating two
embryonic stem cell lines from human embryos produced through SCNT
(Noggle et al. 2011). Three years earlier, a small San Diego
biotechnological company created human embryos (at the blastocyst
stage) via SCNT but did not succeed in deriving embryonic stem cells
from these cells (French et al. 2008). Cloning for research and
therapy is thus not likely to bear fruit in the short term though
progress is made (Tachibana et al. 2013). Apart from unsolved
technical difficulties, much more basic research in embryonic stem
cell research is needed. The term ‘therapeutic cloning’
has been criticized precisely for this reason. It suggests that
therapy using embryonic stem cells from cloned embryos is already
reality. In the phase before clinical trials, critics say, it is only
reasonable to refer to research on nuclear transfer as ‘research
cloning’ or ‘cloning for biomedical research’ (PCBE,
2002).

Cloning for research and therapy holds great potential for future
research and therapeutic applications, but it also raises various ethical
concerns.

Much of the debate about the ethics of cloning for research and
therapy turns on a basic disagreement about how we should treat early
human embryos. As it is currently done, the isolation of embryonic
stem cells involves the destruction of embryos at the blastocyst stage
(day five after fertilization, when the embryo consists of
125–225 cells). But cloning for research and therapy not only
involves the destruction of embryos, it also involves the creation of
embryos solely for the purpose of stem cell derivation.
Views on whether and when it is permissible to create embryos solely
to obtain stem cells differ profoundly.

Some believe that an embryo, from the moment of conception, has the
same moral status, that is, the same set of basic moral rights, claims
or interests as an ordinary adult human being. This view is sometimes
expressed by saying that the early embryo is a person. On this view,
creating and killing embryos for stem cells is a serious moral
wrong. It is impermissible, even if it could save many lives (Deckers
2007). Others believe that the early embryo is merely a cluster of
cells or human tissue lacking any moral status. A common view among
those who hold this position is that, given its promising potential,
embryonic stem cell and cloning research is a moral imperative
(Devolder & Savulescu 2006). Many defend a view somewhere in
between these opposing positions. They believe, for example, that the
early embryo should be treated with respect because it has an
intermediate moral status: a moral status lower than that of a person
but higher than that of an ordinary body cell. A popular view amongst
those who hold this position is that using embryos for research might
sometimes be justified. Respect can be demonstrated, it is typically
argued, by using embryos only for very important research that cannot
be done using less controversial means, and by acknowledging the use
of embryos for research with a sense of regret or loss (Robertson
1995; Steinbock 2001). One common view among those who hold the
intermediate moral status view is that the use of discarded IVF
embryos to obtain stem cells is compatible with the respect we owe to
the embryo, whereas the creation and use of cloned embryos is not. An
argument underlying this view is that, unlike IVF embryos, cloned
embryos are created for instrumental use only; they are created and
treated as a mere means, which some regard as incompatible with
respectful treatment of the embryo (NBAC 1999). Others (both
proponents and opponents of embryo research) have denied that there is
a significant moral difference between using discarded IVF embryos and
cloned embryos as a source of stem cells. They have argued
that if killing embryos for research is wrong, it is wrong
regardless of the embryo’s origin (Doerflinger 1999; Fitzpatrick
2003; Devolder 2005, 2015). Douglas and Savulescu (2009) have argued
that it is permissible to destroy ‘unwanted’ embryos in
research, that is, embryos that no one wishes to use for reproductive
purposes. Since both discarded IVF embryos and cloned embryos created
for the purpose of stem cell derivation are unwanted embryos in that
sense, it is, on their view, permissible to use both types of embryos
for research.

A less common view holds that obtaining stem cells from cloned embryos
poses fewer ethical problems than obtaining stem cells from
discarded IVF embryos. Hansen (2002) has advanced this view, arguing
that embryos resulting from SCNT do not have the same moral status we
normally accord to other embryos: he calls the combination of a
somatic nucleus and an enucleated egg a “transnuclear
egg”, which, he says, is a mere “artifact” with no
“natural purpose” or potential “to evolve into an
embryo and eventually a human being,” and therefore falls
outside the category of human beings. McHugh (2004) and Kiessling
(2001) advance a similar argument. On their view, obtaining stem cells
from cloned embryos is less morally problematic because embryos
resulting from SCNT cannot (yet) develop further, and are thus better
thought of as tissue culture, whereas IVF represents instrumental
support for human reproduction. Since creating offspring is not the
goal, they argue, it is misleading to use the term
‘embryo’ or ‘zygote’ to refer to the product
of SCNT. They suggest to instead use the terms ‘clonote’
(Mc Hugh) and ‘ovasome’ (Kiessling).

Cloning for research and therapy requires a large number of high-quality donor
oocytes. Ethical issues arise regarding how these oocytes could be
obtained. Oocyte donation involves various risks and discomforts (for a
review of the risks, see Committee on Assessing the Medical Risks of
Human Oocyte Donation for Stem Cell Research, 2007). Among the
most pressing ethical issues raised by participating in such donation is what
model of informed consent should be applied. Unlike women who are
considering IVF, non-medical oocyte donors are not clinical patients.
They do not stand to derive any reproductive or medical benefit
themselves from the donation (though Kalfoglou & Gittelsohn,
2000, argue that they may derive a psychological benefit). Magnus and
Cho (2005) have argued that donating women should not be classified as
research subjects since, unlike in other research, the risks to the
donor do not lie in the research itself but in the procurement of the
materials required for the research. They suggest that a new category
named ‘research donors’ be created for those who expose
themselves to substantial risk only for the benefit of others (in this
case unidentifiable people in the future) and where the risk is
incurred not in the actual research but in the procurement of the
materials for the research. Informed consent for altruistic organ
donation by living donors to strangers has also been suggested as a
model, since, in both cases, the benefits will be for strangers and not
for the donor. Critics of this latter suggestion have pointed out,
however, that there is a disanalogy between these two types of
donation. The general ethical rule reflected in regulations concerning
altruistic donation, namely that there must be a high chance of a good
outcome for the patient, is violated in the case of oocyte donation for
cloning research (George 2007).

Given the risks to the donor, the absence of direct medical benefit
for the donor, and the uncertain potential of cloning research, it is
not surprising that the number of altruistic oocyte donations for such
research is very low. Financial incentives might be needed to increase
the supply of oocytes for cloning research. In some countries,
including the US, selling and buying oocytes is legal. Some object to
these practices because they consider oocytes as integral to the body
and think they should be kept out of the market: on their view, the
value of the human body and its parts should not be expressed in terms
of money or other fungible goods. Some also worry that, through
commercialization of oocytes, women themselves may become objects of
instrumental use (Alpers &Lo 1995). Many agree, however, that a
concern for commodification does not justify a complete ban on payment
of oocyte donors and that justice requires that they be financially
compensated for the inconvenience, burden, and medical risk they
endure, as is standard for other research subjects (Steinbock 2004;
Mertes &Pennings 2007). A related concern is the effect of
financial or other offers of compensation on the voluntariness of
oocyte donation. Women, especially economically disadvantaged women
from developing countries, might be unduly induced or even coerced
into selling their oocytes (Dickinson 2002). Baylis and McLeod (2007)
have highlighted how difficult it is concomitantly to avoid both undue
inducement and exploitation: a price that is too low risks
exploitation; a price that avoids exploitation risks undue
inducement.

Concerns about exploitation are not limited to concerns about
payment, as became clear in the ‘Hwang scandal’ (for a
review, see Saunders & Savulescu 2008). In 2004,
Woo-Suk-Hwang, a leading Korean stem cell scientist, claimed to be the
first to clone human embryos using SCNT and to extract stem cells from
these embryos. In addition to finding that Hwang had fabricated many of
his research results, Korea’s National Bioethics Committee also
found that Hwang had pressured junior members of his lab to donate
oocytes for his cloning experiments.

Some authors have argued that a regulated market in oocytes
could minimize ethical concerns raised by the commercialization of
oocytes and could be consistent with respect for women (Resnik 2001;
Gruen 2007). Researchers are also investigating the use of
alternative sources of oocytes, including animal oocytes, fetal
oocytes, oocytes from adult ovaries obtained post mortem or during
operation, and stem cell-derived oocytes. Scientists have already
succeeded in creating human oocytes from embryonic stem cells (Ma et
al. 2017; Saitou & Miyauchi 2016). Finally, another option is
‘egg-sharing’ where couples who are undergoing IVF for
reproductive purposes have the option to donate one or two of their
oocytes in return for a reduced fee for their fertility treatment. The
advantage of this system is that it avoids exposing women to extra
risks – these women were undergoing IVF in any case (Roberts
& Throsby 2008).

Personalized cloning therapies are likely to be labor intensive and
expensive. This has raised social justice concerns. Perhaps cloning
therapies will only be a realistic option for the very rich? Cloning
therapies may, however, become cheaper, less labor intensive and more
widely accessible after time. Moreover, cloning may cure
diseases and not only treat symptoms. Regardless of the economic cost,
it remains true of course that the cloning procedure is time consuming,
rendering it inappropriate for certain clinical applications where
urgent intervention is required (e.g., myocardial infarction, acute
liver failure or traumatic or infectious spinal cord damage). If
cloning for therapy became available, its application would thus likely
be restricted to chronic conditions. Wilmut (1997), who cloned Dolly,
has suggested that cloning treatments could be targeted to maximize
benefit: an older person with heart disease could be treated with stem
cells that are not a genetic match, take drugs to suppress her immune
system for the rest of her life, and live with the side-effects; a
younger person might benefit from stem cells from cloned embryos that
match exactly. Devolder and Savulescu (2006) have argued that
objections about economic cost are most forceful against ‘cloning
for self-transplantation’ than, for example, against cloning for
developing cellular models of human disease. The latter will enable
research into human diseases and may result in affordable therapies and
cures for a variety of common diseases, such as cancer and heart
disease, which afflict people all over the world. Finally, some have
pointed out that it is not clear whether cloning research is
necessarily more labor intensive than experiments on cells and tissues
now done in animals.

Some are skeptical about the claimed benefits of cloning for research
and therapy. They stress that for many diseases in which cloned
embryonic stem cells might offer a therapy, there are alternative
treatments and/or preventive measures in development, including gene
therapy, pharmacogenomical solutions and treatments based on
nanotechnology. It is often claimed that other types of stem cells
such as adult stem cells and stem cells from the umbilical cord blood
might enable us to achieve the same aims as cloning. Especially
induced pluripotent stem cells (iPSCs) have raised the hope that
cloning research is superfluous (Rao & Condic 2008). iPSCs are
created through genetic manipulation of a body cell. iPSCs are similar
to embryonic stem cells, and in particular to embryonic stem cells
from cloned embryos. However, iPSC research could provide tissue- and
patient-specific cells without relying on the need for human oocytes
or the creation and destruction of embryos. iPSC research could thus
avoid the ethical issues raised by cloning. This promise
notwithstanding, scientists have warned that it would be premature to
stop cloning research as iPSCs are not identical to embryonic stem
cells (Pera & Trounson 2013). Cloning research may teach us
things that iPSC research cannot teach us. Moreover, iPSC research
has been said to fail to completely avoid the issue of embryo
destruction (Brown 2009, Devolder 2015).

Slippery slope arguments express the worry that permitting a certain
practice may place us on a slippery slope to a dangerous or otherwise
unacceptable outcome. Several commentators have argued that accepting
or allowing cloning research is the first step that would place us on a
slippery slope to reproductive cloning. As Leon Kass (1998, 702) has
put it: “once the genies put the cloned embryos into the bottles,
who can strictly control where they go?”

Others are more skeptical about slippery slope arguments against
cloning and think that effective legislation can prevent us from
sliding down the slope (Savulescu 1999; Devolder & Savulescu
2006). If reproductive cloning is unacceptable, these critics say, it
is reasonable to prohibit this specific technology rather than to ban
non-reproductive applications of cloning. The UK and Belgium, for
example, allow cloning research but prohibit the transfer of cloned
embryos to the uterus.

Apart from the question of how slippery the slope might be, another
question raised by such arguments concerns the feared development
–reproductive cloning– and whether it is really ethically
objectionable. Profound disagreement exists about the answer to this
question.

The central argument in favor of reproductive cloning is expansion of
opportunities for reproduction. Reproductive cloning could offer a new
means for prospective parents to satisfy their reproductive goals or
desires. Infertile individuals or couples could have a child that is
genetically related to them. In addition, individuals, same sex
couples, or couples who cannot together produce an embryo would no
longer need donor gametes to reproduce if cloning were available (some
might still need donor eggs for the cloning procedure, but these would
be enucleated so that only the mitochondrial DNA remains). It would
then be possible to avoid that one’s child shares half of her nuclear
DNA with a gamete donor.

Using cloning to help infertile people to have a genetically related
child, or a child that is only genetically related to them, has been
defended on the grounds of human wellbeing, personal autonomy, and the
satisfaction of the natural inclination to produce offspring
(Häyry 2003; Strong 2008). Offering individuals or couples the
possibility to reproduce using cloning technology has been said to be
consistent with the right to reproductive freedom, which, according to
some, implies the right to choose what kind of children we will have
(Brock 1998, 145).

According to some, the main benefit of reproductive cloning is that
it would enable prospective parents to control what genome their
children will be endowed with (Fletcher 1988, Harris 1997, 2004;
Pence 1998, 101–6; Tooley 1998). Cloning would enable parents to have
a child with a genome identical to that of a person with good health
and/or other desirable characteristics.

Another possible use of reproductive cloning is to create a child
that is a tissue match for a sick sibling. The stem cells from the
umbilical cord blood or from the bone marrow of the cloned child could
be used to treat the diseased sibling. Such ‘saviour
siblings’, have already been created through sexual reproduction
or, more efficiently, through a combination of IVF, preimplantation
genetic diagnosis and HLA testing.

Many people, however, have expressed concerns about human
reproductive cloning. For some, these concerns are sufficient to reject
human cloning. For others, these concerns should be weighed against
reasons for reproductive cloning.

What follows is an outline of some of the main areas of concern and
disagreement about human reproductive cloning.

Despite the successful creation of viable offspring via SCNT in
various mammalian species, researchers still have limited understanding
of how the technique works on the subcellular and molecular level.
Although the overall efficiency and safety of reproductive cloning in
mammals has significantly increased over the past fifteen years, it is
not yet a safe process (Whitworth & Prather 2010). For
example, the rate of abortions, stillbirths and developmental
abnormalities remains high. Another source of concern is the risk of
premature ageing because of shortened telomeres. Telomeres are
repetitive DNA sequences at the tip of chromosomes that get shorter as
an animal gets older. When the telomeres of a cell get so short that
they disappear, the cell dies. The concern is that cloned animals may
inherit the shortened telomeres from their older progenitor, with
possibly premature aging and a shortened lifespan as a result.

For many, the fact that reproductive cloning is unsafe provides a
sufficient reason not to pursue it. It has been argued that it would
simply be wrong to impose such significant health risks on humans. The
strongest version of this argument states that it would be wrong now to
produce a child using SCNT because it would constitute a case of
wrongful procreation. Some adopt a consent-based objection and condemn
cloning because the person conceived cannot consent to being exposed to
significant risks involved in the procedure (Kass 1998; PCBE 2002).
Against this, it has been argued that even if reproductive cloning is
unsafe, it may still be permissible if there are no safer means to
bring that very same child into existence so long as the child is
expected to have a life worth living (Strong 2005).

With the actual rate of advancement in cloning, one cannot exclude a
future in which the safety and efficiency of SCNT will be comparable or
superior to that of IVF or even sexual reproduction. A remaining
question is, then, whether those who condemn cloning because of its
experimental nature should continue to condemn it morally and legally.
Some authors have reasoned that if, in the future, cloning becomes
safer than sexual reproduction, we should even make it our reproductive
method of choice (Fletcher 1988; Harris 2004, Ch. 4).

3.2.1 A Threat to Autonomy

Some fear that cloning threatens the identity and individuality of
the clone, thus reducing her autonomy (Ramsey 1966; Kitcher 1997;
Annas 1998; Kass 1998). This may be bad in itself, or bad because it
might reduce the clone’s wellbeing. It may also be bad because it
will severely restrict the array of life plans open to the clone, thus
violating her ‘right to an open future’ (a concept
developed in Feinberg 1980). In its report ‘Human Cloning and
Human Dignity: An Ethical Inquiry’, the US President’s
Council on Bioethics (2002) wrote that being genetically unique is
“an emblem of independence and individuality” and allows us
to go forward “with a relatively indeterminate future in front of
us” (Ch. 5, Section c). Such concerns have formed the basis of
strong opposition to cloning.

The concern that cloning threatens the clone’s identity and
individuality has been criticized for relying on the mistaken belief
that who and what we become is entirely determined by our genes. Such
genetic determinism is clearly false. Though genes influence our
personal development, so does the complex and irreproducible context in
which our lives take place. We know this, among others, from studying
monozygotic twins. Notwithstanding the fact that such twins are
genetically identical to each other and, therefore, sometimes look very
similar and often share many character traits, habits and preferences,
they are different individuals, with different identities
(Segal 2000). Thus, it is argued, having a genetic duplicate does not
threaten one’s individuality, or one’s distinct
identity.

Brock (2002) has pointed out that one could nevertheless argue that
even though individuals created through cloning would be unique
individuals with a distinct identity, they might not experience it that
way. What is threatened by cloning then is not the individual’s
identity or individuality, but her sense of identity and
individuality, and this may reduce her autonomy. So even if a clone has
a unique identity, she may experience more difficulties in establishing
her identity than if she had not been a clone.

But here too critics have relied on the comparison with monozygotic
twins. Harris (1997, 2004) and Tooley (1998), for example, have pointed
out that each twin not only has a distinct identity, but generally also
views him or herself as having a distinct identity, as do their
relatives and friends. Moreover, so they argue, an individual created
through cloning would likely be of a different age than her progenitor.
There may even be several generations between them. A clone would thus
in essence be a ‘delayed’ twin. Presumably this would make
it even easier for the clone to view herself as distinct from the
progenitor than if she had been genetically identical to someone her
same age.

However, the reference to twins as a model to think about reproductive
cloning has been criticized, for example, because it fails to reflect
important aspects of the parent-child relationship that would incur if
the child were a clone of one of the rearing parents (Jonas 1974;
Levick 2004). Because of the dominance of the progenitor, the risk of
reduced autonomy and confused identity may be greater in such a
situation than in the case of ordinary twins. Moreover, just
because the clone would be a delayed twin, she may have the
feeling that her life has already been lived or that she is
predetermined to do the same things as her progenitor (Levy &
Lotz 2005). This problem may be exacerbated by others constantly
comparing her life with that of the progenitor, and having problematic
expectations based on these comparisons. The clone may feel under
constant pressure to live up to these expectations (Kass 1998; Levick
2004, 101; Sandel 2007, 57–62), or may have the feeling she leads
‘a life in the shadow’ of the progenitor (Holm 1998; PCBE
2002, Ch.5). This may especially be the case if the clone was
created as a ‘replacement’ for a deceased child. (Some
private companies already offer to clone dead pets to create
replacements pets.) The fear is that the ‘ghost of the dead
child’ will get more attention and devotion than the replacement
child. Parents may expect the clone to be like the lost child, or some
idealized image of it, which could hamper the development of her
identity and adversely affect her self-esteem (Levick 2004, 111–132).
Finally, another reason why the clone’s autonomy may be reduced
is because she would be involuntarily informed about her genetic
predispositions. A clone who knows that her genetic parent developed a
severe single gene disease at the age of forty will realise it is very
likely that she will undergo the same fate. Unlike individuals who
choose to have themselves genetically tested, clones who know
their genetic parent’s medical history will be involuntarily
informed.

These concerns have been challenged on several grounds. Some believe
that it is plausible that, through adequate information, we could
largely correct mistaken beliefs about the link between genetic and
personal identity, and thus reduce the risk of problematic expectations
toward the clone (Harris 1997, 2004; Tooley 1998, 84–5; Brock 1998,
Pence 1998). Brock (1998) and Buchanan et al. (2000, 198)
have argued that even if people persist in these mistaken beliefs and
their attitudes or actions lead to cloned individuals
believing they do not have an open future, this does not imply
that the clone’s right to ignorance about one’s personal
future or to an open future has actually been violated. Pence
(1998, 138) has argued that having high expectations, even if based on
false beliefs, is not necessarily a bad thing. Parents with high
expectations often give their children the best chances to lead a happy
and successful life. Brock (2002, 316) has argued that parents now also
constantly restrict the array of available life plans open to their
children, for example, by selecting their school or by raising them
according to certain values. Though this may somewhat restrict the
child’s autonomy, there will always be enough decisions to take
for the child to be autonomous, and to realize this. According to
Brock, it is not clear why this should be different in the case of
cloning. He also points out that there may be advantages to being a
‘delayed twin’ (154). For example, one may acquire
knowledge about the progenitor’s medical history and use this
knowledge to live longer, or to increase one’s autonomy. One
could, for example, use the information to reduce the risk of getting
the disease or condition, or to at least postpone its onset, by
behavioral changes, an appropriate diet and/or preventive medication.
This would not be possible, however, if the disease is untreatable (for
example, Huntington’s Disease). Harris (2004, Ch.1) has stressed
that information about one’s genetic predispositions for certain
diseases would also allow one to take better informed reproductive
decisions. Cloning would allow us to give our child a ‘tried and
tested’ genome, not one created by the genetic lottery of sexual
reproduction and the random combination of chromosomes.

3.2.2 The clone will be treated as a means

Cloning arouses people’s imagination about the clone, but also
about those who will choose to have a child through cloning. Often
dubious motives are ascribed to them: they would want a child
that is ‘just like so-and-so’ causing people to view children
as objects or as commodities like a new car or a new house (Putnam
1997, 7–8). They would want an attractive child (a clone of Scarlett
Johansson) or a child with tennis talent (a clone of Victoria Azarenka)
purely to show off. Dictators would want armies of clones to achieve
their political goals. People would clone themselves out of vanity.
Parents would clone their existing child so that the clone can serve as
an organ bank for that child, or would clone their deceased child to
have a replacement child. The conclusion is then that cloning is wrong
because the clone will be used as a mere means to others’ ends.
These critiques have also been expressed with regard to other forms of
assisted reproduction; but some worry that individuals created through
cloning may be more likely to be viewed as commodities because their
total genetic blueprint would be chosen – they would be
“fully made and not begotten” (Ramsey 1966; Kass 1998;
PCBE 2002, 107).

Strong (2008) has argued that these concerns are based on a fallacious
inference. It is one thing to desire genetically related children, and
something else to believe that one owns one’s children or that one
considers one’s children as objects, he writes. Other commentators,
however, have pointed out that even if parents themselves do not
commodify their children, cloning might still have an impact on
society as a whole, thereby increasing the tendency of others to do so
(Levy & Lotz 2005; Sandel 2007). A related concern expressed by
Levick (2004, 184–5) is that allowing cloning might result in a
society where ‘production on demand’ clones are sold for
adoption to people who are seeking to have children with special
abilities – a clearer case of treating children as objects.

But suppose some people create a clone for instrumental reasons, for
example, as a stem cell donor for a sick sibling. Does this imply that
the clone will be treated merely as a means? Critics of this argument
have pointed out that parents have children for all kinds of
instrumental reasons, including the benefit for the husband-wife
relationship, continuity of the family name, and the economic and
psychological benefits children provide when their parents become old
(Harris 2004, 41–2, Pence 1998). This is generally not considered
problematic as long as the child is also valued in its own right. What
is most important in a parent-child relationship is the love and care
inherent in that relationship. They stress the fact that we judge
people on their attitudes toward children, rather than on their motives
for having them. They also deny that there is a strong link between
one’s intention or motive to have a child, and the way one will
treat the child.

3.2.3 Societal Prejudice and Respect for Clones

Another concern is that clones may be the victims of unjustified
discrimination and will not be respected as persons (Deech 1999;
Levick 2004, 185–187). Savulescu (2005, Other Internet
Resources) has referred to such negative attitudes towards clones as
‘clonism’: a new form of discrimination against a group of
humans who are different in a non-morally significant way. But does a
fear for ‘clonism’ constitute a good reason for rejecting
cloning? Savulescu and others have argued that, if it is, then we must
conclude that racist attitudes and discriminatory behavior towards
people with a certain ethnicity provides a good reason for people with
that ethnicity not to procreate. This, according to these critics, is
a morally objectionable way to solve the problem of racism. Instead of
limiting people’s procreative liberty we should combat existing
prejudices and discrimination. Likewise, it is argued, instead of
prohibiting cloning out of concern for clonism, we should combat
possible prejudices and discrimination against clones (see also Pence
1998, 46; Harris 2004, 92–93). Macintosh (2005, 119–21)
has warned that by expressing certain concerns about cloning one may
actually reinforce certain prejudices and misguided stereotypes about
clones. For example, saying that a clone would not have a personal
identity prejudges the clone as inferior or fraudulent (the idea that
originals are more valuable than their copies) or even less than human
(as individuality is seen as an essential characteristic of human
nature).

3.2.4 Complex Family Relationships

Another concern is that cloning threatens traditional family
structures; a fear that has come up in debates about homosexuals
adopting children, IVF and other assisted reproduction techniques. But
in cloning the situation would be more complex as it may blur
generational boundaries (McGee 2000) and the clone would likely be
confused about her kinship ties (Kass 1998; O’Neil 2002, 67–68).
For example, a woman who has a child conceived through cloning would
actually be the twin of her child and the woman’s mother would,
genetically, be its mother, not grandmother. Some have argued against
these concerns, replying that a cloned child would not necessarily be
more confused about her family ties than other children. Many have four
nurturing parents because of a divorce, never knew their genetic
parents, have nurturing parents that are not their genetic parents, or
think that their nurturing father is also their genetic father when in
fact he is not. While these complex family relationships can be
troubling for some children, they are not insurmountable, critics say.
Harris (2004, 77–78) argues that there are many aspects about the
situation one is born and raised in that may be troublesome. As with
all children, the most important thing is the relation with people who
nurture and educate them, and children usually know very well who these
people are. There is no reason to believe that with cloning, this will
be any different. Onora O’Neil (2002, 67–8) argues that such
responses are misplaced. While she acknowledges that there are already
children now with confused family relationships, she argues that it is
very different when prospective parents seek such potentially confused
relationships for their children from the start.

Other concerns related to cloning focus on the potential harmful
effects of cloning for others. Sometimes these concerns are related to
those about the wellbeing of the clone. For example, McGee’s concern
about confused family relationships not only bears on the clone but
also on society as a whole. However, since I have already mentioned
this concern, I will, in the remainder of this entry, focus on other
arguments

3.3.1 Adoption and the Importance of Genetic Links

The strongest reason for why reproductive cloning should be
permissible, if safe, is that it will allow infertile people to have a
genetically related child. This position relies on the view that
having genetically related children is morally significant and
valuable. This is a controversial view. For example, Levy and Lotz
(2005) and Rulli (2016) have denied the importance of a genetic link
between parents and their children. Moreover, they have argued that
claiming that this link is important will give rise to bad
consequences, such as reduced adoption rates (and, in Rulli’s case, a
failure to fulfil one’s duty to adopt) and diminished resources for
improving the life prospects of the disadvantaged, including those
waiting to be adopted. Levick (2004, 185) and Ahlberg and Brighouse
(2011) have also advanced this view. Since, according to these
authors, these undesirable consequences would be magnified if we
allowed human cloning, we have good reason to prohibit it. In
response, Strong (2008) has argued that this effect is uncertain, and
that there are other, probably more effective, ways to help such
children or to prevent them from ending up in such a
situation. Moreover, if cloning is banned, infertile couples may make
use of donor embryos or gametes rather than adoption.

3.3.2 Genetic Diversity

Another concern is that because cloning is an asexual way of
reproducing it would decrease genetic variation among offspring and, in
the long run, might even constitute a threat to the human race. The
gene pool may narrow sufficiently to threaten humanity’s
resistance to disease (AMA 1999, 6). In response, it has been argued
that if cloning becomes possible, the number of people who will choose
it as their mode of reproduction will very likely be too low to
constitute a threat to genetic diversity. It would be unlikely to be
higher than the rate of natural twinning, which, occurring at a rate of
3.5/1000 children, does not seriously impact on genetic diversity.
Further, even if millions of people would create children through
cloning, the same genomes will not be cloned over and over: each person
would have a genetic copy of his or her genome, which means the result
will still be a high diversity of genomes. Others argue that, even if
genetic diversity were not diminished by cloning, a society that
supports reproductive cloning might be taken to express the view that
variety is not important. Conveying such a message, these authors say,
could have harmful consequences for a multicultural society.

3.3.3 Eugenics

Some see the increase in control of what kind of genome we want to
pass on to our children as a positive development. A major concern,
however, is that this shift ‘from chance to choice’ will
lead to problematic eugenic practices.

One version of this concern states that cloning would, from the
outset, constitute a problematic form of eugenics. However, critics
have argued that this is implausible: the best explanations of what was
wrong with immoral cases of eugenics, such as the Nazi eugenic
programs, are that they involved coercion and were motivated by
objectionable moral beliefs or false non-moral beliefs. This would not
necessarily be the case were cloning to be implemented now (Agar 2004;
Buchanan 2007). Unlike the coercive and state-directed eugenics of the
past, new ‘liberal eugenics’ defends values such as
autonomy, reproductive freedom, beneficence, empathy and the avoidance
of harm. Enthusiasts of so-called ‘liberal eugenics’ are
interested in helping individuals to prevent or diminish the suffering
and increase the well-being of their children by endowing them with
certain genes.

Another version of the eugenics concern points out the risk of a
slippery slope: the claim is that cloning will lead to objectionable
forms of eugenics—for example, coercive eugenics—in the
future. After all, historical cases of immoral eugenics often developed
from earlier well intentioned and less problematic practices (for a
history of eugenics as well as an analysis of philosophical and
political issues raised by eugenics, see Kevles 1985 and Paul 1995).
According to Sandel (2007, Ch.5), for example, ‘liberal
eugenics’ might imply more state compulsion than first appears:
just as governments can force children to go to school, they could
require people to use genetics to have ‘better’
children.

A related concern expressed by Sandel (2007, 52–7) is that cloning, and
enhancement technologies in general, may result in a society in which
parents will not accept their child for what it is, reinforcing an
already existing trend of heavily managed, high-pressure child-rearing
or ‘hyper-parenting’. Asch and Wasserman (2005, 202) have
expressed a similar concern; arguing that having more control over what
features a child has can pose an “affront to an ideal of unconditioned
devotion”. Another concern, most often expressed by disability
rights advocates, is that if cloning is used to have
‘better’ children, it may create a more intolerant climate
towards the disabled and the diseased, and that such practices can
express negative judgments about people with disabilities. This
argument has also been advanced in the debate about selective abortion,
prenatal testing, and preimplantation genetic diagnosis. Disagreement
exists about whether these effects are likely. For example, Buchanan
et al. (2002, 278) have argued that one can devalue disability
while valuing existing disabled people and that trying to help parents
who want to avoid having a disabled child does not imply that society
should make no efforts to increase accessibility for existing people
with disabilities.

UNESCO’s Universal Declaration on the Human Genome and Human
Rights (1997) was the first international instrument to condemn human
reproductive cloning as a practice against human dignity. Article 11 of
this Declaration states: “Practices which are contrary to
human dignity, such as reproductive cloning of human beings, shall not
be permitted…” This position is shared by the World
Health Organization, the European Parliament and several other
international instruments. Critics have pointed out that the reference
to human dignity is problematic as it is rarely specified how human
dignity is to be understood, whose dignity is at stake, and how dignity
is relevant to the ethics of cloning (Harris 2004, Ch.2, Birnbacher
2005, McDougall 2008,). Some commentators state that it is the copying
of a genome which violates human dignity (Kass 1998); others have
pointed out that this interpretation could be experienced as an offence
to genetically identical twins, and that we typically do not regard
twins as a threat to human dignity (although some societies in the past
did), nor do we prevent twins from coming into existence. On the
contrary, IVF, which involves an increased ‘risk’ of having
twins, is a widely accepted fertility treatment.

Human dignity is most often related to Kant’s second
formulation of the Categorical Imperative, namely the idea that we
should never use a person merely as a means to an end. I have, however,
already discussed this concern in section 4.2.2.

No unified religious perspective on human cloning exists; indeed,
there are a diversity of opinions within each individual religious
tradition. For an overview of the evaluation of cloning by the main
religious groups see, for example, Cole-Turner (1997) and Walters
(2004). For a specifically Jewish perspective on cloning, see, for
example, Lipschutz (1999), for an Islamic perspective, Sadeghi (2007)
and for a Catholic perspective, Doerflinger (1999).